/*******************************************************************************
 * Software Name : RCS IMS Stack
 *
 * Copyright (C) 2010-2016 Orange.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 ******************************************************************************/

package com.gsma.rcs.core.ims.protocol.msrp;

/**
 * MSRP utility functions
 * 
 * @author jexa7410
 */
public class MsrpUtils {
    /**
     * Get the chunk size
     * 
     * @param header MSRP header
     * @return Size in bytes or 0 for "*" range
     */
    public static int getChunkSize(String header) {
        if (header == null) {
            return -1;
        }
        int index1 = header.indexOf("-");
        int index2 = header.indexOf("/");
        if ((index1 != -1) && (index2 != -1)) {
            try {
                int lowByte = Integer.parseInt(header.substring(0, index1));
                String highByteString = header.substring(index1 + 1, index2);
                if (highByteString.equals("*")) {
                    return 0;
                }
                int highByte = Integer.parseInt(highByteString);
                return (highByte - lowByte) + 1;
            } catch (NumberFormatException e) {
                return -1;
            }
        }
        return -1;
    }

    /**
     * Get the total size
     * 
     * @param header MSRP header
     * @return Size in bytes
     */
    public static int getTotalSize(String header) {
        if (header == null) {
            return -1;
        }
        int index = header.indexOf("/");
        if (index != -1) {
            try {
                return Integer.parseInt(header.substring(index + 1));
            } catch (NumberFormatException e) {
                return -1;
            }
        }
        return -1;
    }
}
